1. Field of the Invention
The present invention relates to engines and more particularly to an engine having at least one curved or angular connecting rod that couples at least one piston to a crankshaft, which is offset from a centerline that extends through the piston bore.
2. Description of the Prior Art
Engines of having various designs and configurations power automobiles, lawn mowers, generators, compressors, and more. Most internal combustion engines are comprised of similar components, which typically include a block, a crankshaft, a piston and a connecting rod that couples the piston with the crankshaft. The connecting rod is crucial in that it transfers the reciprocating power of the piston to the rotating crankshaft. The most common connecting rod design is straight, rotatably connected at one end to a wrist pin in the piston and at the other end to a crankpin on the crankshaft. Many prior art engine designs have attempted to increase efficiency and power by altering the length and configuration of the connecting rods.
One prior art engine design uses a compound connecting rod having separate upper and lower connecting rod sections that are pivotably coupled to one another at one end. The opposite ends of the rod sections are coupled to the piston and crankshaft. A separate sleeve is disposed beneath the piston and is attached to the lower rod section at a pivot point. This design provides an improved level of engine efficiency but increases the overall number of component parts and the likelihood of mechanical failure. Moreover, the complex geometry and multiple pivot points of the compound linkage create increased manufacturing and maintenance costs.
Other prior art designs attempt to increase the functional length of the connecting rods by slidably mounting a piston slide within the piston skirt or in the piston crown. This arrangement provides a pivot point for the connecting rod that is independent of the piston wrist pin and compensates for cyclic changes in the connecting rod effective length. However, much like the compound connecting rods, this connecting rod design is overly complex, suffering from manufacturing and maintenance costs that outweigh the benefits gained in power and efficiency. Reliability of an engine is oftentimes more important than modest gains in performance.
Accordingly, what is needed is an engine design that provides increased levels of efficiency and power without increasing relative manufacturing and maintenance costs or decreasing reliability. Such an engine design should also be able to provide desired output ranges with a reduced overall engine size.